Pre-Flowering & Sexing: Getting to Know Your Plants

As your cannabis plants transition from vegetative growth toward flowering, they enter the **pre-flowering stage**—a critical window where you begin to see early signs of sex. This phase usually begins 1–2 weeks after switching to a 12/12 light cycle indoors, or as daylight naturally shortens outdoors.

Knowing how to identify male and female plants early helps you prevent pollination in sinsemilla grows, select breeding stock if desired, and prepare your space for the bloom phase. This guide will walk you through the pre-flowering stage, how to spot sex organs, and why stable genetics—like those from *Original Sensible Seeds*—make this process more predictable and stress-free.

What Is the Pre-Flowering Stage?

Pre-flowering is the short transitional period between vegetative growth and full flowering. During this time, your plants stop stretching and begin forming early signs of their reproductive parts.

This phase typically lasts 1–2 weeks and is when most photoperiod plants reveal their sex if they haven’t already. For autoflowers, sexing often happens automatically around week 4–5 from sprout.

How to Identify Male and Female Cannabis Plants

Identifying plant sex correctly is crucial—especially if you’re growing for flower and want to avoid seedy buds. Here’s what to look for:

Female Plants

• – Appear first as small calyxes with two white hairs (pistils) growing at the nodes (where branches meet stems).
• – Often take a little longer to show than males.
• – Desired in most grow setups for their ability to produce buds.

Male Plants

• – Appear as small round balls (pollen sacs) at the nodes.
• – Develop faster than females—usually visible by day 7–10 of pre-flower.
• – Should be removed quickly from flowering rooms unless you’re breeding.

Watch for Hermaphrodites

Some plants can show both male and female traits, especially when stressed or if the genetics are unstable. These are called hermaphrodites, and they can pollinate themselves or neighboring plants. If you spot a plant with both pistils and pollen sacs, it’s best to remove it unless you’re experienced with controlled breeding.

Why Genetics Matter in Pre-Flowering & Sexing

Good genetics lead to less guesswork. With well-bred feminized seeds—like those from *Original Sensible Seeds*—you can expect nearly 100% female plants, eliminating the need for sexing altogether. Their stable lines also reduce the chances of hermaphrodites, giving you more peace of mind as you enter the flowering stage.

If you’re looking for reliable feminized seeds, the [best sellers](https://www.originalsensible.com/cannabis-seeds/best-sellers) at Original Sensible Seeds are a great starting point. These strains are popular among growers for their consistency in sexing and flowering performance.

Final Thoughts

The pre-flowering stage is your last chance to inspect your plants before they enter full bloom. Learn to spot male and female signs early, and choose your genetics wisely. With proper attention and strong starting stock, this phase will be smooth, setting you up for a rewarding flowering cycle ahead.